The Seahawksonly will do business with credit cards bearing addresses from Oregon, Washington, Montana, Idaho, Alaska and Hawaii, along with the Canadian provinces, the newspaper reported.

It's a move that teams across all sports have the freedom to employ, and often do. Especially in Denver, where the Broncos announced Sunday that they'll only ship AFC title game tickets to valid billing addresses in Colorado, New Mexico, Utah, Wyoming, Nebraska, Montana, South Dakota and western Kansas.

Niners fans are known travelers. Team play-by-play man Ted Robinson described Charlotte's Bank of America Stadium as being packed with San Francisco faithful for Sunday's win over the Panthers. Seattle -- with the most raucous home-field advantage in the NFL -- isn't risking an enemy intrusion.